1. Field of the Invention
The present invention relates to a sliver piecing method, a sliver piecing machine and a sliver piecing system in a spinning machine such as a roving frame, a drawing frame or the like.
2. Description of the Related Art
Various kinds of automation have recently been made for saving human labor and improving productivity in a spinning mill, and automation of the sliver piecing work in a spinning machine such as a roving frame, a drawing frame or the like has also been proposed (for example, see Japanese Patent Laid-Open No. 2-91233). In this case, as shown in FIG. 44, cans 202 containing sliver S under spinning, and full sliver cans 203 in reserve containing sliver S to be newly supplied are disposed adjacent to each other in plural rows along the lengthwise direction (the direction vertical to the drawing of FIG. 44) of a roving frame 201. A silver piecing machine 204 is moved on traveling rails 206 which are extended along the can rows above feed rollers 205 for guiding the sliver S to the roving frame 201. The feed rollers 205 are respectively disposed opposite to the centers of the cans 202 and 203 above the can rows along the lengthwise direction of the roving frame 201. The sliver piecing machine 204 is provided with an arm 208 having a sliver holding unit 207 and a silver piecing unit 209. The arm 208 is formed so as to be extension and horizontally movable in the direction vertical to the feel rollers 205.
In the sliver piecing work, the sliver S which is being spun and which is continued from the roving frame 201 is introduced into the introduction portion of the sliver piecing unit 209 and is held by the silver piecing unit 209. In spinning, the sliver S is introduced into the introduction portion of the sliver piecing unit 209 by a sliver taking-in arm (not shown) provided on the sliver piecing unit 209. The sliver holding unit 207 then holds the sliver S on the upstream side of the sliver piecing unit 209 (on the side of the cans), and is moved in the direction away from the sliver piecing unit 209 to cut the silver S. The sliver holding unit 207 then holds the end of the sliver S contained in the full sliver can 203 and introduces the end into the introduction portion of the sliver piecing unit 209 so as to overlap the introduced end and the end of the cut sliver held by the sliver piecing unit 209. In the state wherein the overlapped portions of both slivers S are held, the sliver holding unit 207 is then moved in the direction away from the sliver piecing unit 209 to cut the new sliver S. The slivers are then pieced together by operation of the sliver piecing unit 209. Namely, in the sliver piecing machine 204, the sliver S is introduced into the introduction portion of the sliver piecing unit 209 in the state wherein the sliver S is horizontally extended. In addition, the arm 208 is moved above the feed rollers 205 so as to cut the sliver S and introduce the sliver S into the introduction portion of the sliver piecing unit 209.
Japanese Patent Laid-Open No. 2-91233 also discloses a sliver piecing method of piecing slivers S which are vertically extended. In this method, a single feed roller 205 is provided for a row of cans 202 and a row of full sliver cans 203, and a guide 210 is disposed opposite to the boundary between both can rows, as shown in FIG. 45. A sliver piecing machine 211 which is moved on traveling rails 206 disposed under the feed rollers 205 comprises an arm 212 having a sliver holding unit (not shown) and provided at the end thereof. The arm 212 is rotated in a plane vertical to the direction of movement of the sliver piecing machine 211 so that the sliver holding unit is moved to a position opposite to the upper portion of the sliver piecing unit (not shown) provided on the upper portion of the front of the sliver piecing machine 211 and the end of the sliver S contained in each of the cans 203. In spinning, the sliver S is introduced into the introduction portion of the sliver piecing unit by a sliver taking-in arm (not shown) provided on the sliver piecing unit.
In the piecing method in which the feed roller 205 is provided for each can row, it is necessary for working to move the arm 208, above the feed rollers 205, for a distance about twice the diameter of each can in the direction vertical to the feed rollers 205. As a result, the size of the sliver piecing machine is increased. In addition, since the sliver S which is being spun is cut by the arm 208 in the state wherein the sliver S is introduced into the introduction portion of the sliver piecing unit 209, and the silver S to be newly supplied is also introduced into the introduction portion by the same arm 208, the sliver piecing work requires much time, coupled with a long moving distance of the arm 208.
On the other hand, in the latter method disclosed in Japanese Patent Laid-Open No. 2-91233, the moving distance of the arm 212 is shorter than that in the former method. However, both methods are the same in the point that the sliver S under spinning is cut by the arm 212 in the state wherein the sliver S is introduced into the introduction portion of the sliver piecing unit, and the sliver S to be newly supplied is also introduced by the same arm 212. Thus, the time required for piecing the slivers together cannot be reduced by concurrently performing the work of cutting the sliver S under spinning and the work of introducing the sliver S to be newly supplied into the introduction portion.
In addition, in this sliver piecing method, the sliver S which is being spun out must be introduced into the introduction portion of the sliver piecing unit 209 between the guides 210 and the cans 202. The movement path of the sliver piecing machine 211 cannot be set so that the sliver piecing unit 209 is close to the sliver S under spinning. It is thus necessary for introducing the sliver S under spinning into the introduction portion of the sliver piecing unit 209 to hold the sliver S by the sliver taking-in arm after guiding the sliver S to a portion near the introduction portion. On the other hand, the sliver S under spinning is obliquely drawn out toward the guide 210 from any desired position in the corresponding can 202 near the periphery thereof. As a result, the position of the sliver S extended from the guide 210 to the can 202 is unfixed excepting a portion downwardly extended by its own weight near the guide 210.
The feed rollers 205 for guiding the supplied sliver to a spinning machine cannot be set at a very height in view of the case in which the sliver S must be manually placed on the feed rollers 205 when the kind of the sliver S is exchanged or the sliver S is cut by a cause of some kind during spinning. If the height of the feed rollers 205 is about 180 cm, and the height of the cans 202 is about 100 cm, the difference between the heights of the feed rollers 205 and the upper ends of the cans 202 is about 80 cm. In each of the cans 202, the bottom on which the sliver is placed is generally upwardly urged by a spring, and is lifted with decreases in the amount of the sliver contained therein. When each can is substantially emptied, the upper end of the sliver is kept at substantially the same height as the upper end of the can. Since the sliver piecing machine 211 is moved under the feed rollers 205, the distance between the guides 210 provided on the traveling rails 206 and the upper ends of the cans is smaller than 80 cm. The portion of the sliver S downwardly extended by its own weight near each of the guides 210 is thus shortened.
When the sliver S is guided to a portion near the introduction portion, it is necessary not to pull a portion of the sliver S on the downstream side (on the side of the roving frame) of a position where the sliver S is held or engaged. The sliver S must thus be held or engaged at a position near the can 202 at a distance from the guide 210 and guided to a position near the introduction portion. However, since the position of the sliver S is unfixed at a position near the cans 202, as described above, there are the problems that a sensor for detecting the position of the sliver S is required, and the mechanism and control for moving a holding or unit to the position near the cans 202 are complicated and require much time. Further, the range of movement of the holding or engaging unit must be widened, thereby causing the problem of increasing the size of the entire apparatus.
A full sliver can row in reserve is disposed adjacent to each of the sliver can rows under spinning so that the empty can (the can from which the sliver has been completely supplied) need not be moved in the process of piecing slivers. On the other hand, the sliver piecing work is performed in the state where the operation of the roving frame is stopped. The size of each sliver can is generally increased for increasing the operation efficiency of the roving frame by increasing the period of the sliver piecing work. As a result, in the roving machine, since the sliver cans under spinning cannot be arranged in a row corresponding to each of weights, sliver cans are arranged in plural rows behind the robing frame base. The sliver cans are sometimes in three or four rows. However, when the sliver cans under spinning are arranged in plural rows, if the conventional sliver piecing method is employed, plural rows of full sliver cans in reverse must be arranged corresponding to the rows of the sliver cans under spinning. As a result, a large area is required for arranging the cans, and the sliver spun out from the cans arranged in the last row might be irregularly drafted in the course of spinning because the sliver is supplied to the roving frame at a long distance therefrom.
In general, plural rows of sliver cans under spinning are thus arranged near the roving frame, and rows of full sliver cans in reserve are arranged behind them. In this arrangement of the sliver can rows, after the sliver S under spinning is cut, the sliver cannot be pieced with another sliver until the can row of the cut sliver S is replaced by the full sliver can row. It is thus impossible to employ the conventional sliver piecing method in which the sliver S under spinning is cut in the introduction portion of the sliver piecing unit, and the cut end must be held at the position.